U.S. Pat. Nos. 3,260,597 and 3,265,498 disclose controlling the density of a Dmin range referred to as "fog" by using a development inhibitor or a development inhibitor precursor in a color diffusion transfer photographic element.
In these patents, the density of the Dmin region which is effected by the acting time is controlled by using a development inhibitor for an image-receiving layer or the acting time of a development inhibitor is controlled by using a precursor capable of releasing a development inhibitor in a hydrolysis reaction. However, the compounds illustrated in these patents inhibit not only the unnecessary development but also the necessary development, whereby the image quality is greatly reduced.
Furthermore, the photographic development reaction is greatly influenced by temperature, i.e., development proceeds slowly at low temperature but proceeds quickly at high temperature. In particular, excessive development is liable to occur at high temperature, whereby the density in a Dmin region increases which results in greatly reducing image quality. Accordingly, it has been desired to find a development inhibitor precursor which can enlarge the allowable processing temperature region by inhibiting the occurrence of unnecessary development at about room temperature, controlling the necessary development so that the development is not inhibited, and inhibiting the occurrence of excessive development at high temperature.
Japanese Patent Publication No. 17369/80 and Japanese Patent Publication (Unexamined) No. 77842/81 disclose development inhibitor precursors for controlling the acting time of development inhibitors by controlling the reaction rate of hydrolysis.
Furthermore, Japanese Patent Publication (Unexamined) No. 130929/79 discloses a development inhibitor precursor which suppresses the occurrence of unnecessary development only by controlling the reaction rate of hydrolysis by temperature, that is, by restraining the increase of the reaction rate of hydrolysis below about room temperature beyond what is necessary and also enlarge the allowable region of processing temperature by sufficiently increasing the reaction rate of hydrolysis at high temperature to control the occurrence of excessive development.
However, the compounds illustrated in the foregoing Japanese Patent Publication No. 17369/80 and Japanese Patent Publication (Unexamined) Nos. 77842/81 and 130929/79 cause a reduction in density in the maximum color density (Dmax) region of an image when these compounds are incorporated in photographic elements and preserved in such a state, which results in greatly reducing image quality. Also, when the photographic elements using these development inhibitor precursors are preserved for a long period of time or are preserved at a high temperature and/or a high humidity, the reduction in image quality becomes greater to the extent that it substantially reduces the commercial value of the photographic elements.
Considering the molecular weights of the compounds illustrated in the foregoing patent publications, it is considered to be reasonable that these compounds unavoidably diffuse in the photographic elements and they diffuse more and more when the photographic elements are preserved for a long period of time although the details have not yet been clarified.
On the other hand, in Japanese Patent Publication No. 34927/80 and Japanese Patent Publication (Unexamined) No. 138745/80, there are illustrated organic ballasting group-containing development inhibitor precursors which become substantially nondiffusible in photographic elements.
However, when a photographic element containing such a development inhibitor precursor having an organic ballasting group as illustrated in the foregoing patent publications is preserved for a long period of time, the density at the Dmax areas is also reduced, which results in greatly reducing image quality. The reason is believed to be that since these compounds are substantially nondiffusible, the releasing rate of development inhibitors by hydrolysis is undesirable.